Among the conventionally-known working machines are ones which include a gas engine mounted on the machine body, a handle column extending rearwardly and upwardly from the machine body and a storage case (hereinafter referred to as “gas canister cover unit”) provided along a handle post, and in which a cassette gas canister is attached to and accommodated in the gas canister cover unit. One example of such working machines is disclosed in Japanese Patent Application Laid-Open Publication No. HEI-10-131809 (JP 10-131809 A).
In the gas-engine-mounted working machine disclosed in the No. HEI-10-131809 publication, the gas engine can be driven by fuel gas supplied from the cassette gas canister to the gas engine. Thus, if the gas-engine-mounted working machine is constructed as a cultivating (tilling) machine, cultivating claws can be rotated so that the machine can travel forward while cultivating the soil by means of the rotating cultivating claws.
Further, in the gas-engine-mounted working machine disclosed in JP 10-131809 A, the gas canister cover unit is fixed to a handle post, and the gas canister is protected by being accommodated in the gas canister cover unit. The gas canister has a great diameter as compared to that of the handle post, and thus, the gas canister cover unit having the gas canister accommodated therein too has a greater width than the handle post. Because the gas canister cover unit having the gas canister accommodated therein is greater in width than the handle post, left and right side wall portions of the gas canister cover unit project laterally leftward and rightward beyond the handle post.
Therefore, during operation of the gas-engine-mounted working machine, ambient obstacles, such as trees or crops, might interfere with left and right walls of the gas canister cover unit. Further, during storage into a given place, the left and right walls of the gas canister cover unit might undesirably contact and be interfered with by ambient obstacles. For these reasons, there is a need to enhance the rigidity of the gas canister cover unit so as to endure the interference from ambient obstacles; however, enhancing the rigidity of the gas canister cover unit would prevent reduction in size and cost of the gas canister cover unit.